1. Field of the Invention
The present invention relates to the transmission of data packets between Local Area Networks (LAN) interconnected by a crossbar switch and relates in particular to a system for transmitting LAN data packets through a crossbar switch.
2. Background of the Invention
Local Area Networks such as ethernet or token-ring, are generally interconnected together through hubs or bridges. The hub is a system made of LAN adapters that communicate together through a switch card. This switch card can be either a parallel bus or a passive switch card. Each data packet sent through the network has to follow a specific data path to reach its final destination. This process is generally known as the expansion mode process which is determinant for the high speed switches. In order to address this concern the prior art solutions are based on the use of a table routing located in front of the switch for rerouting the data packets coming from one port to another output port. Based on the table routing content, the mechanism allows to change the destination address of the incoming data packet in order to re-route this latter to the appropriate switch. In the prior art systems, it is necessary to change a specific field in the packet header to route the packet, and to repeat this replacement as much as it is required for the packet to reach its final destination, which is particularly constraining.
Therefore, it would be desirable to have a routing process and an associated system which overcome the drawbacks of the prior art systems.